44 
Frank Carney 
lished that the glacial period in the East was also composite;^^ 
but a parallelism of epochs has not been worked out. 
For the purposes of the present paper, however, it is assumed 
that the Lake Region of New York had been glaciated previous 
to the Late Wisconsin stage, an hypothesis already used by others 
and that the interval or intervals of deglaciation were not shorter 
than the time-ratios held tentatively for the Mississippian area. 
Illustrations of the wave-cutting work done by some of the 
Finger Lakes since they were lowered to their present levels are 
common in geological literature.^^ One who is acquainted with 
Seneca Lake will recall the high cliff on the east shore near Wat- 
kins, at the head of the lake; and other localities along this lake 
show quite as marked wave-work. Along the present shore of 
Keuka Lake the cliffs are not so well developed, but benches of 
20 feet or more are not uncommon. 
If lakes occupied these longitudinal valleys during the interims 
of glaciation, cliff-cutting could have proceeded to such an extent 
as to make survival in certain localities, at least, probable. Even 
the shortest inter-glacial period, on the assumption that the stages 
of the ice age represent oscillations of the ice from continuously 
ice-covered dispersion areas, was much longer than post-Wiscon- 
sin time, which has sufficed for defining exact shore lines. But 
terrace No. 3 has an altitude that is impossible if the body of 
water with which it is genetically connected discharged over any 
of the present cols leading into the Susquehanna area; all of the 
overflow channels reported for the Keuka valley are too low. It 
may be said, however, that many of these interlocking valleys 
of the St. Lawrence-Susquehanna basins, through which the waters 
of the high-level ice-front lakes spilled, have local characteristics 
which are not normal to the regular development of valleys; the 
conditions here alluded to will be discussed in a separate paper, 
R. D. Salisbury, GeoL Surv. of New Jersey, Ann. Rep. for pp. 73, etc.; 
J. B. Woodworth, N. Y. State Mus., Bulletin 48, pp. 618-670, 1901; F. Carney, 
Journal Geology^ vol. xv (pp. 571-585), 1907. 
R. S. Tarr, American Geologist, vol. xxxiii, p. 282, 284, 1904; H. L. Fairchild, 
Bulletin Geol. Soc. Am., vol. xvi, p. 66, 1905. 
Natural Hist, of N. IT., Part IF, Geology, p. 192, 1843; R. S. Tarr, Elementary 
Geology, p. 279, 1898; LeConte, Elements of Geology, p. 236, 1905. 
